This invention relates generally to unique copolymer alloys useful, for example, in bodies for collecting and retaining hydrocarbon-like contaminant spills on water, as well as non-point source aqueous contaminants, and to methods of making those copolymer alloys and bodies. More particularly, this application relates to unique copolymer compositions found to have remarkably unexpected properties and applications in the collection and retention of hydrocarbon-like contaminants in or on water. The present invention further relates to remediation of environmental contaminants from both point source and non-point sources in and on water.
The continuing incidence of oil spillage into both marine and inland waterways, because of shipping accidents and the like, results in enormous annual costs financially to the shipping and insurance industries and is environmentally hazardous and costly. Furthermore, in many industries, environmental contaminants are released with wastewater, or result from spills at the manufacturing facility. These contaminants can be oil-like materials and enter the environment with waste-and-run-off water. Generally, these manufacturing wastes are in much smaller quantities than the petroleum spills mentioned above, but these materials can be much more environmentally hazardous. They may not require the large specialized equipment associated with marine petroleum spills, but containment and remediation is critical.
Many materials are presently known to be oil-absorbent or oil-adsorbent, such as wood chips, other forms of cellulose, activated carbon, wool, cotton balls, corn husks, duck feathers, and certain synthetic polymeric materials. A number of polymeric materials such as polypropylene, the polyesters, polyurethanes, vinyl polymers, and other hydrocarbon-like polymers may be employed, with varying efficiencies.
Sorbents can be divided into three basic categories: natural organic, natural inorganic, and synthetic. Natural organic sorbents include peat moss, straw, hay, sawdust, ground corncobs, feathers, and other readily available carbon-based products. Natural inorganic sorbents include clay, perlite, vermiculite, glass wool, sand, or volcanic ash. Synthetic sorbents include man-made materials that are similar to plastics, such as polyurethane, polyethylene, and nylon fibers. Many existing sorbents tend to soak up water as well as oil, causing them to sink. Many existing sorbents are loose particles such as sawdust, and are difficult to collect after they are spread on the water. Adding flotation devices, such as empty drums attached to sorbent bales of hay, can help alleviate the sinking problem, and wrapping loose particles in mesh can aid in collection.
Previously existing hydrophobic compositions used to absorb or adsorb hydrocarbons have had one or more of the following problems: (1) in powder or small particulate form, they have been difficult to collect after deployment; (2) larger bodies have not floated in water after absorbing contaminants; (3) large bags of compositions such as polypropylene require large amounts of material; and (4) the compositions fail to adquately encapsulate the hydrocarbons, permitting leaching of the hydrocarbons over time.
The present invention is useful in both point source and non-point source contamination remediation, providing desirable characteristics before, during, and after deployment to remediate contamination via unique contaminant-sorbing copolymers which possess an unexpected synergistic propensity to capture and restrain contaminants such as oil spills and like hydrocarbon contaminants. The present invention also provides unique compositions that are both micro- and macro-porous, which further greatly enhances the abilities of devices formed according to the invention.
The present invention is of a polymer alloy comprising a block copolymer thermoplastic elastomer comprising a microscopic porosity rapidly plasticized by environmental contaminants and a binder of a polymer or copolymer, the binder binding block copolymer particles while preserving the microscopic porosity and providing a macroscopic porosity to allow fluid penetration. In the preferred embodiment, an interfacial alloy exists between the block copolymer and the binder. The block copolymer preferably comprises styrene-butadiene-styrene (SBS) triblock copolymer, styrene-butadiene (SB) diblock copolymer, or styrene-isoprene-styrene,(SIS) triblock copolymer, or a combination thereof, and the binder preferably comprises styrene-ethylene-butylene copolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, or styrene-butene/butylene (SBB) copolymer or a combination thereof. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and the alloy may consist or, or consist essentially of, these two substances.
The invention is also of a polymer alloy comprising a block copolymer, namely styrene-butadiene-styrene (SBS), styrene-butadiene (SB) diblock copolymer, or styrene-isoprene-styrene (SIS) triblock copolymer, and a binder of a polymer or copolymer. In the preferred embodiment, the binder comprises styrene-ethylene-butadiene (SEB) terpolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, or styrene-butene butadiene (SBB) terpolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and the alloy may consist or, or consist essentially of, these two substances.
The invention is further of a polymer alloy comprising a block copolymer thermoplastic elastomer and a binder, namely styrene-ethylene/butylene (SEB) copolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, or styrene-butene/butylene (SBB) copolymer. In the preferred embodiment, the block copolymer thermoplastic elastomer comprises a member selected from the group consisting of styrene-butadiene-styrene (SBS), styrene-butadiene (SB) diblock copolymer, and styrene-isoprene-styrene (SIS) triblock copolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and the alloy may consist or, or consist essentially of, these two substances.
The invention is additionally of a method of producing a polymer alloy comprising: a) providing particles of a block copolymer thermoplastic elastomer comprising a microscopic porosity rapidly plasticized by environmental contaminants; and b) binding the particles with a binder selected from the group consisting of polymers and copolymers while preserving the microscopic porosity and providing a macroscopic porosity to allow fluid penetration. In the preferred embodiment, binding comprises establishing diffusion of the binder into the block copolymer. A further step of thermal annealing at a temperature approximately 5xc2x0 C. lower than a softening point of the block copolymer is preferably employed, preferably for approximately 45 minutes at approximately 27-93xc2x0 C. An additional step of sizing the block copolymer particles by grinding without adding a parting agent is preferably employed, preferably to approximately 6-24 mesh. The alloy may be formed by extrusion, compression molding, or injection molding. The block copolymer preferably comprises styrene-butadiene-styrene (SBS) triblock copolymer, styrene-butadiene (SB) diblock copolymer, and styrene-isoprene-styrene (SIS) triblock copolymer, and the binder preferably comprises styrene-ethylene/butylene (SEB) copolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, and styrene-butene/butylene (SBB) terpolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and formation is by extrusion of the bound particles.
The invention is also of a method of producing a polymer alloy comprising: a) providing particles of a block copolymer thermoplastic elastomer, namely styrene-butadiene-styrene (SBS) triblock copolymer, styrene-butadiene (SB) diblock copolymer, or styrene-isoprene-styrene (SIS) triblock copolymer; and b) binding the particles with a binder selected from the group consisting of polymers and copolymers. In the preferred embodiment, the binder comprises styrene-ethylene-butylene (SEB) copolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, or styrene-butene/butylene (SBB) copolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and formation is by extrusion of the bound particles.
The invention is further of a method of producing a polymer alloy comprising: a) providing particles of a block copolymer thermoplastic elastomer; and b) binding the particles with a binder selected from the group consisting of styrene-ethylene-butadiene (SEB) terpolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, and styrene-butene butadiene (SBB) terpolymer. In the preferred embodiment, the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer, styrene-butadiene (SB) diblock copolymer, or styrene-isoprene-styrene (SIS) triblock copolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and formation is by extrusion of the bound particles.
The invention is additionally of a material for recovering hydrocarbon contaminants from water comprising a polymer alloy comprising: a) particles having micro-porous spaces for infiltration and capture of hydrocarbons; b) a binder composition connecting the particles to neighbor particles; and c) macro-porous spaces adjacent to substantially all of the particles permitting infiltration of hydrocarbons substantially throughout the material. In the preferred embodiment, the particles comprise styrene-butadiene-styrene (SBS) triblock copolymer, styrene-butadiene (SB) diblock copolymer, and styrene-isoprene-styrene (SIS) triblock copolymer, and the binder comprises styrene-ethylene/butylene (SEB) copolymer, ethylene-propylene-diene monomer (EPDM) terpolymer, ethylene-propylene (EPR) copolymer, and styrene-butene butadiene (SBB) terpolymer. Most preferably the block copolymer comprises styrene-butadiene-styrene (SBS) triblock copolymer and the binder comprises ethylene-propylene-diene monomer (EPDM) terpolymer, and the alloy may consist or, or consist essentially of, these two substances. The material is preferably formed into a tubular body or bodies and deployed onto a contaminant spill to remediate the spill. The bodies may be formed into collectivities within bags, blankets, bales, booms, pillows, and filters.
A primary object of the present invention is to provide a contaminant sorbing composition and system that is hydrophobic, highly contaminant absorbent, and readily collectible, floats after absorbing contaminants, and does not leach contaminants.
A primary advantage of the present invention is that the combined micro- and macro-porous nature of the copolymer alloy of the invention permits the primary object of the invention to be realized.
Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.